Floor-cramp.



W. l. BURRIDGE.

FLGOR CRAMP.

APPLICATION HLED SEPT. 25. 1914.

1 1 86,277. Patented June 6, 1916.

THE CULUMBIA PLANDGRAPH co., WASHINGTON. D. C.

UNITED STATES PATENT OFFICE.

WALTER JOI-IN BURRIDGE, OF ST. KILDA, ITICTORIA, AUSTRALIA.

`rincon-canin.

specification of Letters Patent.

Patented June e, 1916.

Application led September 25, 1914. Serial No. 863,423.

the ln'nd adapted to be gripped to a joist by.

means of a serrated cam-shaped gripping member while the board is forcedinto position by a rack bar operated by a pin, a pair of ratchet wheelsof greater diameter than said pinion and a pair of pawls is carried byan operating lever and adapted to said ratchet wheels.

The objects of the present invention are to provide improved retentionmeans for the rack bar and to provide a compact form of cramp.

To these ends and in accordance with this invention a pawl is pivotallylmounted on the carrying bracket of the cramp close to and adapted toengage the ratchet wheels.

The improved cramp consists of a metal bracket piece having at onesidedownwardly projecting grip lugs and at the other side a projectinglug which takes the vertical journal pin of a metal serrated cam grip.The said bracket piece has also upwardly projecting side cheeks betweenwhich is a longitudinal race to receive a toothed metal rack bar and itspinion, the latter being secured on a cross spindle which is supportedin bearings in said side cheeks, while formed integral with and oneither side of said rack pinion are two larger ratchet wheels which arecapable of being operated by a double pawl forked hand lever whichis'also centered on the aforesaid cross spindle outside of the bearingcheeks. The said toothed rack bar has a pressure head at one end, andabove and fitting over it, between the aforesaid side cheeks, is apivoted retention pawl which is acted on by suitable springs or by aspring to retain the toothed rack bar at the position it has been placedby the forked hand lever acting on the ratchet wheels and the attachedratchet portion.

This invention will now be fully described aided by a reference to theattached sheet of drawings in which Figure l is a plan and Fig. 2 a sideview of my improved floor cramp. Fig. 3 a ceni tral longitudinallsection on line 1 1 Fig. l and Fig. 4 a transverse section on lines 2 2also of Fig. l ybut drawn to a smaller scale.

In said figures A sthe 'bracket piece, B the sliding toothed rack bar,B1 the toothed pinion gearing therewith and centered on vspindle B2carried 1n bearings in side cheeks a of said bracket piece, B3 are theratchet wheels formed integral with the toothed pinion B1 and hencealsoarranged upon spindle B2.

C is the hand lever having its lower forked end centered upon spindle B2outside of 'aforesaid side cheeks a, and said lever carries a doublepawl C1 centered on spindle c carried in the forked part of hand leverC, the pawl C1 being furnished with a thumb piece c1 by which it may bereleased from the ratchets B3.

D is a double toothed retention pawl also designed to.`engage withratchet wheels B3 it being centered on a pin Z furnished with bearingsin the side cheeks a of bracket piece. The pawl D has a backwardlyprojecting integral presser or foot piece D1 which is seated on springsE while E1 is a central rollerto work on the upper face of the rack-barB.

At one side of bracket piece is a bossed lug a1 furnished with a hole toreceive a ver tical journal pin a2 the upper end of which is fitted witha key or short lever F1 while upon or formed integral with thel pin a2below the bracket piece is a cam grip piece F which is designed to gripone side of the flooring joist G the other side of which is gripped bythe pins or serrations a3 on the inner face of the lower grip lugs at.

VIt is by working the key or lever F1 that the cam grip F is firstpressed against or released from the joist which lies between it and theaforesaid pinned or serrated cheek lugs while the floor boards areforced into position byA means of the sliding rack bar B being operatedby the pinion B1 whose integral ratchet wheels are rotated by the pawllever C, the rack bar being held at the required position to maintainthe strain by the spring retention pawl D.

Having now described my invention what I claim as new and desire tosecure by Letters Patent is 1. An improved floor cramp consisting of ametal bracket piece having at one side doiv ivardly projecting grip lugsand at the other side a 'projecting lug having a vertical boss, a pinjournaled in said bess7 a gripping member journaled on said pin, saidbrat-ker, member being also ormed with upwardly projecting side Cheeksproviding a longitudinal race, a rack bar movable in said race betweenthe side Cheeks, a Cross spindle journaled in the side cheeks, a pinioniriXed thereto, ratchet wheels of larger diameter formed integral withsaid pinion on either side thereof, a lever straddling the side Cheeksand pivoted to said pin, pavvls Carried b v the lever and side Cheeksrespeetivel,7 to engage the ratchet wheels at diametrieally oppositepoints, one oi said pawls being spring-pressed and adapted to bedepressed for disengaging the saine, and said pawls preventing movementot the lever in opposite directions, and a roller journaled between theside cheeks ot the bracket piece and bearing on the rack bar, saidroller and pinion constituting a tivo-point pressure means to guide therack bar during its movement.

Q. In an improved floor cramn the combination of a ratchet leverfurnished with dou ble pawls, two ratchet Wheels formed integral with acentral toothed pinion of much smaller diameter than said :ratchetWheels, a toothed sliding rack bar7 with which said toothed piniongears, a bracket pieee'earrying a spindle for said ratchet lever andtoothed gears, a spring retention paWl, and ay roller journaled on thesupport of the retention pavvl for movement over the rack barsubstantially as described and shown.

In testimony whereof I have signed my name to this speeiiieation in thepresence ot' two subscribing Witnesses.

VALTER JOHN BURRDGE. lVitnesses MEDLINGTON HoDGCoMe, LESLIE Lmv'roNBEAR.

Copies ef this patent may ne obtained for five cents each, by addressingthe Commissioner of Iatents, Washington, D, C.

